1. Field of the Invention
This invention relates to computer-controlled displays of pixel information, and more particularly to a system and method for controlling the display of a movable image within a displayed field to provide intelligent and life-like transitions of the displayed image as it is moved from one position to another position in the displayed field.
2. Description of Related Art
Conventional video game systems commonly rely upon program information and operator controls to form displayable images of a movable person, vehicle, or the like, within a relatively static background field of objects such as trees, roads, rocks, walls, and the like. Such video game systems typically incorporate "joystick" controllers or cursor-control buttons for producing operator control signals that determine the position or direction of movement of the movable object within the background field. In such systems of contemporary design, the movable object as displayed is usually inhibited from moving through an impassable object or area such as a displayed wall, tree or rock, and the system operator is then required to manipulate cursor-control buttons or joystick controller to maneuver the displayed movable object around the displayed impassable objects. In this manner, a system operator maintains control over a movable object as it is continually repositioned and redirected along a desired path among impassable objects within the computer-controlled display. If the movable object is maneuvered into an impassable object such as a rock or tree, then the movable object may not be advanced further in a direction through the impassable object, but will have to be controlled or maneuvered by the system operator in other directions away from the impassable object under computer control. Systems of this type are commercially available and commonly include a console unit to which manual controllers are connected, and to which various memory cartridges can be connected that configure the video game system for operation as a labyrinth game, race, sporting event, or the like.
However, in certain computer-controlled game systems, a conventional "mouse"-type controller may be utilized to position a displayed cursor at a selected position in a conventional manner. It also may be that the system operator wants the object he is controlling to keep moving in some general direction without having to maneuver the object around the impassable object that normally prevents the movable object from continuing on the desired direction. (i.e., A direction key is used to designate travel in an easterly direction and there happens to be an impassable object east of the movable object). When such a controller is arranged to designate a destination for a displayed movable object within a displayed field of impassable objects, a direct path, or trajectory, between where a movable object is positioned in the display and where the operator desires the movable object to be next positioned in the display may intercept an impassable object that inhibits further movement of the movable object toward the desired position without additional maneuvering by the system operator. With a mouse-type controller, such maneuvering may involve awkward repositioning of a displayed cursor, via the "mouse" to overlap the position where the movable object is "stuck" against an impassable object, and thereafter redefine different path segments to maneuver the movable object around the impassable object toward the desired next position. This severely limits the speed with which a computer-controlled game sequence may progress through a sequence of scenes or events, and contributes to operator frustration in having to maintain continuous control over the movable object during even the most trivial repositioning maneuvers associated with a displayed scene or event.